This invention relates to organogermanium compounds having both hydrophilicity and lipophilicity and a process for producing them.
There have been known a number of alkyl- and arylgermanium sesquioxides obtained as hydrolyzates of trialkyl- and triarylgermanes. Of these hydrolyzates, carboxyethylgermanium sesquioxide is drawing attention as an immunotherapeutic agent completely free from toxicity.
Many of the known alkyl- and arylgermanium sesquioxides dissolve little in water and organic solvents. Only the carboxyethylgermanium sesquioxide and some of its derivatives have solubilities of 1 to 2% in water, or only slight hydrophilicity. No lipophilic oxide has ever been available. Thus, without affinity for the lipids that are essential constituents of the living organism, such a prior art compound is retained only for a very short period in the body on account of the metabolism of limited duration. In order that it be efficacious, therefore, its dosage must be relatively increased to disadvantage.
Metallic germanium, the chief material of the germanium compounds, is expensive itself and its annual production is limited. Relative decrease rather than increase in the dosages is an important problem to be solved for conservation of germanium resources as well as from the economical viewpoint.
In view of the foregoing, we have intensively conducted experiments aimed at providing an organogermanium compound which is free of toxicity and achieve the dual purpose of being rapidly absorbed by the patient and excreted from the body while exhibiting and maintaining an effective pharmacological activity per given dose. The present invention has now been perfected after syntheses of numerous compounds.